Blister card packages are commonly used for distribution of many products including pharmaceutical drugs, batteries, sewing kits, toy cars, etc. A blister card package is used as a stiffener or backing sheet for packaging a product contained in a blister, which may comprise a blister strip having a single row of individual blisters, or a solid form blister having a two-dimensional matrix of individual blisters (which will be discussed in more detail below). Typically, the blister card package is comprised of pre-printed stiff paper, such as cardboard, that is folded to create at least two adjacent sides. One or both of the sides typically contain an aperture. The product to be packaged is usually encased in a clear plastic individual blister, which may be inserted between the two adjacent sides of the blister card package such that the product protrudes from one or both apertures. The two cardboard sides are then sealed, typically via application of heat and pressure, to retain the plastic individual blister within its blister card packaging.
Blister card packages may accommodate individual blisters (as illustrated above) or may be designed to accept blister strips or solid form blisters. The latter are commonly used to package pharmaceutical drugs for public distribution or clinical trials. Pharmaceutical drugs are distributed in many forms such as capsule, pill, lozenge, etc., which are amenable to distribution in blister strips or solid form blisters. A blister strip comprises a contiguous strip of plastic individual blisters having a common backing, such as foil, that is one unit wide by any number of units long. In contrast, solid form blisters comprise both horizontal and vertical rows of individual blisters, however, solid form blisters also typically share a common backing.
Blister strips and solid form blisters are popular containers for pharmaceutical drugs because the strips may be specially configured to meet the dosage requirements of the drug. For example, an antibiotic drug prescription may require 16 pills to be taken in a specific order. The blister strip or solid form blister may be manufactured such that the pills are packaged in the same order that the pills should be taken. The blister strip or solid form blister may then be packaged in a pre-printed blister card package that contains printed instructions regarding when and how to take each dose. Additionally, the insertion of one 16-dose strip or one 4-dose wide by 4-dose long solid form blister into a blister card package is much easier to perform than the insertion of 16 distinct blisters arranged in a specific order. Therefore, pharmaceutical drugs distributed to the public or used in clinical trials are typically packaged in blister strips or solid form blisters contained within a sealed blister card package.
Many blister card packaged products, especially pharmaceutical drugs, can be harmful, or even lethal, to children or mentally impaired adults. At the same time, however, the products contained in blister card packages may be vital to the health of other adults including senior citizens, some of which may have impaired physical and cognitive skills and/or poor eyesight. Consequently, it is desirable to manufacture blister card packages that impede a child's access to the product contained in the blister while simultaneously facilitating a senior citizen's access to its content. Such packaging is known in the art and is commonly referred to as child-resistant and senior-friendly packaging.
The federal government has implemented various laws to ensure that materials deemed by the government to be dangerous are packaged in child-resistant and senior-friendly packaging. Specifically, the federal government enacted the Poison Prevention Packaging Act of 1970 (“PPPA”) (Pub. L. 91-601, 84 Stat. 1670, 15 U.S.C. 1471-75) on Dec. 30, 1970, which is incorporated herein by reference. The Poison Prevention Packaging Act of 1970 requires harmful substances to be packaged in child-resistant packaging, i.e., such that children under 5 years of age, having no physical or mental handicaps, cannot “open or obtain a harmful amount of the substance contained therein within a reasonable time” and senior-friendly packaging, i.e., such packaging must also “not [be] difficult for normal adults to use properly.” Notably, the PPPA does not require that children be prevented from opening or obtaining a toxic or harmful amount of the substance 100 percent of the times attempted. When the substance is packaged in individual units, the Code of Federal Regulations requires that child-resistant packaging is effective no less than 80 out of every 100 attempts (16 C.F.R. 1700.15(b) (1)). Conversely, senior adults between ages 50 and 70, having no mental or physical disabilities, should be able to open the packaging no less than 90 out of every 100 attempts when permitted to view printed instructions that accompany the packaging (16 C.F.R. 1700.15(b) (2) (i-ii), 16 C.F.R. 1700.20(a) (3) (i), 16 C.F.R. 1700.20 (a) (3) (iv)).
To ensure compliance with the aforementioned federal guidelines, blister card packaging is submitted to a testing agency, which determines the child-resistance rating and whether or not the packaging is senior-friendly. Packaging is rated as senior-friendly solely based on the 90 percent guideline, i.e., senior adults are able to open the packaging at least 90 times out of every 100 attempts. However, the child resistance rating is determined on a scale ranging from F1 through F8. The F represents “fatal at” and the following number represents the number of doses, therefore, F4 is “fatal at 4 doses.” Consequently, the more difficult it is for a child to access a product contained within a blister card package, the lower the child-resistance rating applied to the packaging. It is intuitive that products contained within packaging rated at F1, i.e., lethal at one dose, should be very difficult for children to access, whereas, products rated at F8, i.e., lethal at 8 doses, do not require the same level of difficulty. A blister card package that is to be used for distribution of potentially lethal pharmaceutical drugs or clinical trial drugs must pass the aforementioned federal guidelines prior to use. Additionally, the child resistance rating will determine what type of pharmaceutical drugs can be distributed within each rating of packaging, i.e., a pharmaceutical drug that is lethal at three doses cannot be packaged in a blister card package that is rated F4 through F8. When the lethal dose of a drug has not been established, federal regulations require an assumption that the drug is lethal at eight doses, therefore, such a drug may be distributed in packaging rated F8.
Blister card packages exist today that have passed the federal child-resistant and senior-friendly testing guidelines. Many existing, patented blister card packages were originally designed for distribution of non-lethal drugs and, therefore, were not required to pass the federal testing guidelines. To sell to a larger market of users, these blister card packages were modified to achieve child-resistance using a variety of methods including adding paperboard layers, adding plastic or tape layers to the exterior of the paperboard, reinforcing a frangible foil backing with a less frangible paper, etc.
After the aforementioned modifications were made, many blister card packages that were previously non-child-resistant were able to pass child resistance testing, however, the packaging became undesirable in other ways. For example, the additional, reinforced layers often prevented the pills from being pushed cleanly through the blister backing and thereby caused degradation of the backing of other adjacent pills. Specifically, some blister card package manufacturers have added a layer of paper to the foil backing through which a pill is pushed. The paper and/or foil backing sometimes does not tear cleanly, leaving the user only one option: scraping the backing until enough of it is removed to allow the user to grasp and peel the backing enough to reach the pill. This can be very difficult, especially for senior citizens or other adults with impaired physical abilities. Additionally, these blister card packages have been manufactured with more than a minimal amount of plastic, which does not make them environmentally viable to produce or dispose after use.
To address some of the concerns mentioned above, manufacturers have looked at alternative forms of packaging for containing medications in secure packages that are sturdy enough to be opened and closed numerous times until the course of medication is completed, yet having a locking function to prevent a child from accessing the medications. Various packages have been utilized comprising a two-piece paperboard container having an internal slide card housing medications and contained within an outer paperboard shell. Many of these devices use an interference locking mechanism wherein the internal slide card abuts with an internal portion of the outer paperboard shell when pulled, thereby preventing access to the slide card. Before pulling the internal slide card, an adult must apply a sufficient force—which is greater than a child can apply—to a push-button tab to release the interference fit. Unfortunately, over time and as a result of repeated uses, the force requirements to release the interference fit can weaken and become ineffective in preventing access by a child. Furthermore, many of these devices do not prevent the slide card from being pulled completely from the paperboard shell upon applying sufficient force to a push-button tab. Yet other packages are not easy to assemble in a flat-laid, pre-glued distribution of a package.
Thus, there is a clear need for child-resistant and senior-friendly packages that have a locking function that achieves a high child resistance rating when tested while remaining easy to use for senior citizens through multiple uses of the package until dosage is depleted. There is a further need for child-resistant and senior-friendly packaging that is environmentally friendly and which requires minimal modifications to a customers established blister layout reducing cost and increasing speed to market.